The invention relates to a "cetane improver" and a method for manufacturing this cetane improver. Cetane improvers are added essentially to all diesel fuel sold in the United States to increase their autoignition properties. Accordingly, the market for such cetane improvers is very large.
Cetane improvers have been used for at least 30 years. They were, for many years, almost exclusively amyl nitrate. The cost of amyl alcohol, from which the amyl nitrate is made, rose and so most of the major suppliers changed to either hexyl, which was used for a brief period of time, or to ethyl hexyl or octyl nitrate because it was cheaper. The alternatives have a higher molecular weight and therefore they are less effective for a given mass. However, because the price difference is now disproportionate to the difference in molecular weight the alternatives have better cost effectiveness.
In addition, lower molecular weight nitrates such as ethyl or propyl nitrates are unstable and hazardous to manufacture and ship.
There are octyl nitrates of two kinds, either the 2-ethyl hexyl nitrate or the n-octyl nitrate. There are only four primary suppliers in the United States. Octyl nitrate is a commodity product which is sold at the approximate rate of 130 million lbs. a year in the United States and the rate is growing by 3% a year. Its profit margin is low, as it is for most commodity items. Consequently small differences in raw materials or processing costs can make large differences in the ultimate cost for a given level of performance.
It is an object of the invention to provide a cost effective cetane improver.
Another object of the invention is to provide a very substantial market for an undesired by-product in the liquor industry--fusel oil.
It is still another object of the invention to minimize the hazard of manufacturing, shipping and storing of the finished product.